How to Divide Hostas

Hostas is a perennial plant with broad oval or lobed leaves that grows from rhizomes (root mass or cluster). They grow well in partial and full shade. The are very hardy and easy to grow. I struggled for years fighting crabgrass in my flower bed bordering the house in the front yard. I tried black plastic, landscaping fabric, various plants, and lots of weeding! Initially, I only had 2 hosta plants. Over the years I learned that hostas was very hardy and would actually beat the weeds. So, I started planting more hosta in this troublesome area and less of other plants. Most of them I received from my Mama or aunt when they divided theirs, but I did buy a very few small plants of different varieties.

Now, I have 33 hostas plants of various varieties. They are beautiful and I love them. However, my L-shaped flower bed that wraps around the corner of the house is over flowing in spots and starting to look like a jungle.

My Oldest Two Varieties of Hostas In Need of Serious Thinning
Just a sampling of my oldest two varieties in need of thinning

Hostas spreads by growing more plants from the rhizome (root). Some of my older plants have really gotten huge and are in dire need of dividing. I have never divided any of them before. To be quite honest I should have divided some of them last year and the year before, but we all know how things like that go sometimes. It would also have been easier to have divided them this year before they fully came out with their leaves, but of course that did not happen either. So, last weekend I finally got around to dividing them.

To Divide Hostas

1) When To Divide?

Most of us gardeners just get out there and divide them in the spring when we see it is abundantly clear they need it. This is not the best practice. It can be traumatic to the plant especially if it is hot. Ideally, it is best to divide hostas 1 month before the first frost in the fall. But as I said, they are tough and resilient.

2) Dig

Dig a circle several inches (4 inches for small plants and 12 inches for larger plants) away from the base of the plant. The larger the plant the further the roots will go out. Take caution not to damage the bulk of the root system. If it is large you will inevitably cut some of the smaller roots.

Up Close Look At Base Of Hostas
Several Small Exposed Roots Around Base of Hostas

Many years ago, I put crushed red brick over a layer of landscaping fabric. It looked lovely and went nicely with the red brick and wine colored trim on our house. However, it has made the last 5 or 6 years of gardening and maintenance a real pain. It is brutal on the hands and fingernails. It is almost impossible to rake away all of the brick without spending all day clearing one spot. I used to just squat and bend over when I gardened. But the last few years that is getting harder and harder to do. I broke down and bought a couple of those foam knee pads that you just lay on the ground and move around as need from the dollar store. My back and knees were thankful. I do not recommend using crushed brick in your beds and I do recommend foam knee pads!

Dig Around Root Base
Dig Around Root Base

3) Identify Plants To Separate

As visible in the above picture there are individual smaller plants in this large plant base clump. It may be helpful to wash the roots off with water so that you can see the individual plants and their rhizomes. This is especially helpful if you have never divided perennial plants before.

4) Divide

If the hostas is not very big you may be able to separate these individual plants and their roots from each other my hand by just carefully pulling apart at the stem and working your way down to through the root. To remove a stem from the crown, use a back and forth pulling motion and not a side-wise motion (hold the core plant in one hand, and grab the stem in the other, rotate the stem-holding back and forth), work the stem back and forth until the rhizome comes loose or breaks from the crown. The rhizome will break at the appropriate point. Even if you lose some of the plant stems, you’ll still have enough of the rhizomes to produce a healthy new clump.

If the plant is large it will be easier to use a serrated kitchen knife, hacksaw, or the sharp end of a shovel/trowel to cut through the clump of rhizomes. Still take care to do this in between the stems of individual plants. Try to keep as many roots and leaves as possible, by making cuts through the crown but not into the roots. If possible, make the cut about half way through the crown and then see if you can pull it apart by hand; use the same back and forth pulling motion. If your plants are monsters like mine you will probably cut off smaller clumps cutting the large clump into thirds or fourths rather than in between each individual plant stem as prying them apart by hand is almost impossible. As a rule, the larger and more dense the clump, the less divisions that are possible. Do not expect to divide these hostas again for the next few years.

5) Place in Water

Immediately after dividing place the “extras” (those to give away or plant in another location) plants into water. Because my hostas is so large, the clumps that I cut divided off still have quite a lot of soil around the roots.

Place Divided Hostas in Water
Just One Clump Cut Off

6) Replant

Replant the main hostas to remain in the original location. Be sure to replant back to its original level on the stem or just slightly deeper. Add more soil if too much is lost from the division of a large hostas plant. Dividing smaller plants probably will not lose enough soil to need replacing.

Two Hostas Plant Replanted in Original Location After Divided

If your hostas is fully leafed out like mine, you may lose a leaf or two and it may look a little sprawled out for a day or two. Don’t worry they will be fine. Be sure to water thoroughly the planted hostas as the roots will dry out some during the process of dividing.

7) Plant, Share with a Friend, or Even Sell New Divided Hostas

I only divided 4 large hostas plants and had 4 3-gallon buckets full of plants to give away. Pictured below is 2 1/2 buckets full. I failed to take a picture of all 4.

See My New Foam Knee Pad Out in the Yard

The new divided hostas can be divided smaller at the time of planting if desired. I just left my large divided clumps in buckets of water to give to my Mama, sisters, and sister-in-law to plant. I will let them separate them more if desired. These large clumps can also just be planted as is for a nice full plant. Space large leafed hostas plants 2 to 3 feet apart. Be sure to dig a hole big enough to fully cover the roots and to water well. Water often the first week or two after transplanting.

For more information on Hosta:
Hosta on Wikipedia

Featured at: